| 摘要 |
PROBLEM TO BE SOLVED: To provide a production method of a high-concentration carburized steel capable of heightening a carbon concentration in a steel material surface, while suppressing deposition of a coarse carbide, in a vacuum carburization step.SOLUTION: Concerning a production method of a high-concentration carburized steel having a vacuum carburization step for introducing a pulse of hydrocarbon gas in a plurality of times into a carburization furnace for holding a steel material under a reduced pressure, in the vacuum carburization step, after introducing once a pulse of hydrocarbon gas, the next pulse is introduced when a carbon concentration in the surface of the steel material becomes below a carbon concentration equivalent to A cm line.SELECTED DRAWING: Figure 1 |
